Background: Wilms' tumour gene 1 (WT1), a highly ranked immunotherapeutic target, is expressed in uterine cancer and therefore WT1 immunotherapy may present an attractive treatment option. Patient and Methods: An HLA-A2.1-positive 46-year-old woman with end-stage serous endometrial cancer received 4 weekly injections of WT1-RNA-loaded dendritic cells. Response was measured clinically (CT scan), biochemically (CA125) and immunologically (WT1-specific T cells). Results: The patient showed WT1 positivity in 10% of tumour cells and diffusely in the intratumoural endothelial cells of the recurrent disease. After 2 injections, CA125 started to decrease and WT1-specific T-cells increased 2.5-fold. The treatment was feasible and there were no treatment-related side-effects. However, the patient, suffering from diffuse disease which became progressive again, died 8 months later. Conclusion: This is the first patient with a WT1-positive endometrial carcinoma, to receive immunotherapy with WT1-RNA-loaded dendritic cells, resulting in a vaccine-specific T cell response.